28664478109 has 2 divisors, whose sum is σ = 28664478110. Its totient is φ = 28664478108.

The previous prime is 28664477983. The next prime is 28664478169. The reversal of 28664478109 is 90187446682.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25667244100 + 2997234009 = 160210^2 + 54747^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28664478109 is a prime.

It is a super-2 number, since 2×28664478109² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 28664478109.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28664478169) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14332239054 + 14332239055.

It is an arithmetic number, because the mean of its divisors is an integer number (14332239055).

Almost surely, 2^28664478109 is an apocalyptic number.

It is an amenable number.

28664478109 is a deficient number, since it is larger than the sum of its proper divisors (1).

28664478109 is an equidigital number, since it uses as much as digits as its factorization.

28664478109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4644864, while the sum is 55.

The spelling of 28664478109 in words is "twenty-eight billion, six hundred sixty-four million, four hundred seventy-eight thousand, one hundred nine".